From 84fdfafab849036b5aefa52824b5cb42e887ef0e Mon Sep 17 00:00:00 2001 From: Lan Tianyu Date: Wed, 27 Feb 2019 22:54:03 +0800 Subject: [PATCH] x86/Hyper-V: Set x2apic destination mode to physical when x2apic is available Hyper-V doesn't provide irq remapping for IO-APIC. To enable x2apic, set x2apic destination mode to physcial mode when x2apic is available and Hyper-V IOMMU driver makes sure cpus assigned with IO-APIC irqs have 8-bit APIC id. Reviewed-by: Thomas Gleixner Reviewed-by: Michael Kelley Signed-off-by: Lan Tianyu Signed-off-by: Joerg Roedel --- arch/x86/kernel/cpu/mshyperv.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index e81a2db42df7..3fa238a137d2 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -328,6 +328,18 @@ static void __init ms_hyperv_init_platform(void) # ifdef CONFIG_SMP smp_ops.smp_prepare_boot_cpu = hv_smp_prepare_boot_cpu; # endif + + /* + * Hyper-V doesn't provide irq remapping for IO-APIC. To enable x2apic, + * set x2apic destination mode to physcial mode when x2apic is available + * and Hyper-V IOMMU driver makes sure cpus assigned with IO-APIC irqs + * have 8-bit APIC id. + */ +# ifdef CONFIG_X86_X2APIC + if (x2apic_supported()) + x2apic_phys = 1; +# endif + #endif }